const (
// TaintNodeNotReady will be added when node is not ready
// and feature-gate for TaintBasedEvictions flag is enabled,
// and removed when node becomes ready.TaintNodeNotReady = "node.kubernetes.io/not-ready"
// DeprecatedTaintNodeNotReady is the deprecated version of TaintNodeNotReady.
// It is deprecated since 1.9DeprecatedTaintNodeNotReady = "node.alpha.kubernetes.io/notReady"
// TaintNodeUnreachable will be added when node becomes unreachable
// (corresponding to NodeReady status ConditionUnknown)
// and feature-gate for TaintBasedEvictions flag is enabled,
// and removed when node becomes reachable (NodeReady status ConditionTrue).TaintNodeUnreachable = "node.kubernetes.io/unreachable"
// DeprecatedTaintNodeUnreachable is the deprecated version of TaintNodeUnreachable.
// It is deprecated since 1.9DeprecatedTaintNodeUnreachable = "node.alpha.kubernetes.io/unreachable"
// TaintNodeUnschedulable will be added when node becomes unschedulable
// and feature-gate for TaintNodesByCondition flag is enabled,
// and removed when node becomes scheduable.TaintNodeUnschedulable = "node.kubernetes.io/unschedulable"
// TaintNodeOutOfDisk will be added when node becomes out of disk
// and feature-gate for TaintNodesByCondition flag is enabled,
// and removed when node has enough disk.TaintNodeOutOfDisk = "node.kubernetes.io/out-of-disk"
// TaintNodeMemoryPressure will be added when node has memory pressure
// and feature-gate for TaintNodesByCondition flag is enabled,
// and removed when node has enough memory.TaintNodeMemoryPressure = "node.kubernetes.io/memory-pressure"
// TaintNodeDiskPressure will be added when node has disk pressure
// and feature-gate for TaintNodesByCondition flag is enabled,
// and removed when node has enough disk.TaintNodeDiskPressure = "node.kubernetes.io/disk-pressure"
// TaintNodeNetworkUnavailable will be added when node's network is unavailable
// and feature-gate for TaintNodesByCondition flag is enabled,
// and removed when network becomes ready.TaintNodeNetworkUnavailable = "node.kubernetes.io/network-unavailable"
// TaintNodePIDPressure will be added when node has pid pressure
// and feature-gate for TaintNodesByCondition flag is enabled,
// and removed when node has enough disk.TaintNodePIDPressure = "node.kubernetes.io/pid-pressure"
// TaintExternalCloudProvider sets this taint on a node to mark it as unusable,
// when kubelet is started with the "external" cloud provider, until a controller
// from the cloud-controller-manager intitializes this node, and then removes
// the taintTaintExternalCloudProvider = "node.cloudprovider.kubernetes.io/uninitialized"
// TaintNodeShutdown when node is shutdown in external cloud providerTaintNodeShutdown = "node.cloudprovider.kubernetes.io/shutdown"
// NodeFieldSelectorKeyNodeName ('metadata.name') uses this as node field selector key
// when selecting node by node's name.NodeFieldSelectorKeyNodeName = api.ObjectNameField
)

PriorityReduceFunction is a function that aggregated per-node results and computes
final scores for all nodes.
TODO: Figure out the exact API of this method.
TODO: Change interface{} to a specific type.

type SchedulerExtender interface {
// Filter based on extender-implemented predicate functions. The filtered list is
// expected to be a subset of the supplied list. failedNodesMap optionally contains
// the list of failed nodes and failure reasons.Filter(pod *v1.Pod,
nodes []*v1.Node, nodeNameToInfo map[string]*schedulercache.NodeInfo,
) (filteredNodes []*v1.Node, failedNodesMap schedulerapi.FailedNodesMap, err error)
// Prioritize based on extender-implemented priority functions. The returned scores & weight
// are used to compute the weighted score for an extender. The weighted scores are added to
// the scores computed by Kubernetes scheduler. The total scores are used to do the host selection.Prioritize(pod *v1.Pod, nodes []*v1.Node) (hostPriorities *schedulerapi.HostPriorityList, weight int, err error)
// Bind delegates the action of binding a pod to a node to the extender.Bind(binding *v1.Binding) error// IsBinder returns whether this extender is configured for the Bind method.IsBinder() bool// IsInterested returns true if at least one extended resource requested by
// this pod is managed by this extender.IsInterested(pod *v1.Pod) bool// ProcessPreemption returns nodes with their victim pods processed by extender based on
// given:
// 1. Pod to schedule
// 2. Candidate nodes and victim pods (nodeToVictims) generated by previous scheduling process.
// 3. nodeNameToInfo to restore v1.Node from node name if extender cache is enabled.
// The possible changes made by extender may include:
// 1. Subset of given candidate nodes after preemption phase of extender.
// 2. A different set of victim pod for every given candidate node after preemption phase of extender.ProcessPreemption(
pod *v1.Pod,
nodeToVictims map[*v1.Node]*schedulerapi.Victims,
nodeNameToInfo map[string]*schedulercache.NodeInfo,
) (map[*v1.Node]*schedulerapi.Victims, error)
// SupportsPreemption returns if the scheduler extender support preemption or not.SupportsPreemption() bool// IsIgnorable returns true indicates scheduling should not fail when this extender
// is unavailable. This gives scheduler ability to fail fast and tolerate non-critical extenders as well.IsIgnorable() bool
}

SchedulerExtender is an interface for external processes to influence scheduling
decisions made by Kubernetes. This is typically needed for resources not directly
managed by Kubernetes.